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Poster: LewTucker Date: Jun 17, 2003 2:48pm
Forum: sflan Subject: DHCP on the ethernet line

Is anyone else having problems getting DHCP through
the ethernet port on our boxes? It's fine through
the wireless access point, but not when connected
by ethernet.

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Poster: TomNash Date: Jun 23, 2003 5:31am
Forum: sflan Subject: Re: DHCP on the ethernet line

I am SFLAN 10 and Clif explained this DHCP problem when we were installing my node. There is a "feature" presently in his software that allows him to set up a node with DHCP either on the omni or on the house ethernet, but not both. He is planning to fix this.

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Poster: brewster Date: Jun 18, 2003 12:52am
Forum: sflan Subject: Re: DHCP on the ethernet line

Yes, I have trouble. We are looking at the architecture of how to blend in with our home networks: this does not work well in my home setup.

Current wishlist:
* get the higher speed sflan when it is working
* fall back transparently to our dsl lines
* can get to our home printers etc

jurgen and clif are looking into how to do this.

any other wishes?


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Poster: TomNash Date: Jun 23, 2003 6:09am
Forum: sflan Subject: Re: DHCP on the ethernet line

I have been busy since Clif was here and we set up SFLAN 10 -- so I haven't had a chance to post some comments re "wishes".

Clif and I discussed some of this, but the simplest way I can say it is to suggest that we use the capabilties of Apple's AirPorts and the associated software as a "requirements document".

Apple has thought this out well and has just the features that people would want for the home ethernet part of an SFLAN installation. This includes a NAT, encryption (for the really nervous), port aliasing (so you can have a web site behind the NAT), DHCP, wireless to ethernet bridging, access control, etc.

Of course, one should prioritize such a list, but in some sense Apple has done that already. They provide those features that their marketing has determined will make their product most successful. I suspect their choices are just what would make SFLAN most successful also (in the sense that more people would want to sign on).

I would even go so far as to suggest that the SFLAN box software could emulate the interface of the AirPorts so that one could use Apple's Airport Admin Utility to configure an SFLAN box. This would make it possible for home users to set up their own boxes without requiring Clif or another admin person to be involved.

I know this is all considerable work, but I make the suggestion because I think this is the kind of thing that would push SFLAN over the top and allow us to get the critical mass that would make this very successful.

One other thing that would help enormously would be more uplink bandwidth to enable private web servers (along with an ip for each site). This might even require a monthly charge since real $ would be involved. I am getting about a third the uplink of PacBell's DSL -- about 45 Mb/s vs about 145Mb/s and neither is enough for a decent web site.

I also think we should be a little clearer about what it takes to connect up to an Omni -- that is one needs some kind of high gain antenna if you are more than 100 ft or so away. That at least is my experience (a lap top wireless card without a special antenna won't work beyond 100 ft or so) and it agrees with what Lew Tucker told me the other night that he would expect.

So the architecture is a bunch of backbone nodes on hilltops (like mine and Lew's) and then small secondary nodes in the neighborhood that are pointing small hi gain antennas at these omnis. Do i get that right?

Hope to meet you all sometime soon.


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Poster: Brak Date: Jun 23, 2003 7:26am
Forum: sflan Subject: Re: DHCP on the ethernet line

Regarding speed, here is the speed I am seeing to each of the hops along the way:

sflan2: 4.92 Mb/sec (3x-5x most DSL)
sflan3: 3.87 Mb/sec
sflan11: 943 Kb/sec
sflan10: 632 Kb/sec (about 0.5x DSL)

I'm not sure why this dropoff is occuring, but it may be correctable.

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Poster: TomNash Date: Jun 23, 2003 9:48am
Forum: sflan Subject: Re: DHCP on the ethernet line

That's consistent with what I am seeing on the downlink -- it measured at 631 kb/s on June 7, about half what I was getting on DSL.

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Poster: akb Date: Jun 18, 2003 4:19am
Forum: sflan Subject: Re: DHCP on the ethernet line

Personally, I always trust traffic from a public wireless network as much as I trust traffic from the Internet, ie not at all. Given how most users are pretty sloppy with things like leaving unpassworded shared folders lying around, I think the default should be a firewall with the option for users to VPN into their own network.

As for the failover between 'net connections, I recently came across a product at a reasonable price that looked promising, though I've not used it myself. The router is from Nexland (Symantec also sells an version with a VPN) and will actually multiplex connections so your potential bandwidth approaches the sum of the two 'net links. If one link goes down it fails over to the other and detects when the failed link is back up. Here's a review:,4149,643459,00.asp

I've not seen an equivalently functioning piece of software in the Open Source world, though it would certainly be possible to do.